1. Field of the Invention
The present invention relates to a method and an apparatus for a wireless communication system. More particularly, the present invention relates to a method and an apparatus for transmitting and receiving a signal in a wireless communication system.
2. Description of the Related Art
A cell radius is very small in a next generation wireless communication system, compared to an existing cellular environment. Also, the cell distribution is irregular according to the operation of various cells, such as a femto cell. Inter-cell interference in such an environment is a major reason of degrading a performance of a User Equipment (UE) according to a packet error of the UE.
In order to address an interference problem in a wireless communication system, it is desirable to accurately estimate an interference signal and channel information on the interference signal. To this end, a Reference Signal (RS) is transmitted on a Orthogonal Frequency Division Multiplexing (OFDM) domain in a wireless communication system (e.g. a Long Term Evolution (LTE) system).
An example of the RS includes a Cell-specific Reference Signal (CRS). The CRS, which is a generally used RS, is transmitted to every UE within each cell. The CRS is transmitted via each antenna in a form of a pseudo random sequence initiated with a cell IDentifier (ID) in order to minimize inter-cell interference. Accordingly, position information on the CRS may be detected based on the cell ID, and a position of a CRS transmission frequency for each antenna is determined within the same symbol according to the number of transmission antennas.
In the meantime, a wireless communication system of the related art using the CRS has a number of shortcomings. For example, in the wireless communication system using the CRS, when a resource used for transmitting the CRS in a first cell among a plurality of cells is the same as that used for transmitting the CRS in a second cell which is a neighboring cell of the first cell, inter-cell interference is generated and exerts influence on the first cell and the second cell. Accordingly, when the UEs located in the respective first and second cells estimate a channel based on the CRS within the corresponding cell, it is desirable to prevent a channel estimation performance from being degraded by removing the interference from the received CRS or compensating for the interference.
Accordingly, in the wireless communication system of the related art, the UE performs an additional operation in order to address the interference problem according to the CRS transmission, so that the complexity according to signal transmission/reception increases and a load of the UE increases.